Clomipramine or its pharmaceutically acceptable salt has been used for treating depression from before, and also has effects on treating or preventing ejaculation delayed (premature ejaculation).
When administering this clomipramine or its pharmaceutically acceptable salt, a side effect of erectile dysfunction may occur, and in order to improve this side effect of erectile dysfunction, studies about administering clomipramine or its pharmaceutically acceptable salt with sildenafil or its pharmaceutically acceptable salt are ongoing.
Furthermore, it was known that sildenafil or its pharmaceutically acceptable salt can be used for treating or improving premature ejaculation because it inhibits contraction of vas deferens, seminal vesicle, prostate and urethra, and shows induction of peripheral analgesia, increase of erection period, inhibition of central sympathetic autonomic nerve reaction. Thus, the present inventors assume that administrating clomipramine or its pharmaceutically acceptable salt and sildenafil or its pharmaceutically acceptable salt at the same time may be more effective to treat or improve premature ejaculation.
However, not much is known about problems which can occur when containing these ingredients in one formulation until now.